The present disclosure relates to a system and method for performing a volume based three-dimensional virtual examination, and more particularly relates to a method providing enhanced visualization and navigation properties.
Two-dimensional (“2D”) visualization of human organs using medical imaging devices has been widely used for patient diagnosis. Currently available medical imaging devices include computed tomography (“CT”) and magnetic resonance imaging (“MRI”), for example. Three-dimensional (“3D”) images can be formed by stacking and interpolating between two-dimensional pictures produced from the scanning machines. Imaging an organ and visualizing its volume in three-dimensional space would be beneficial due to the lack of physical intrusion and the ease of data manipulation. However, the exploration of the three-dimensional volume image must be properly performed in order to fully exploit the advantages of virtually viewing an organ from the inside.
When viewing the 3D volume virtual image of an environment, a functional model must be used to explore the virtual space. One possible model is a virtual camera, which can be used as a point of reference for the viewer to explore the virtual space. Camera control in the context of navigation within a general 3D virtual environment has been previously studied. There are two conventional types of camera control offered for navigation of virtual space. The first gives the operator full control of the camera, which allows the operator to manipulate the camera in different positions and orientations to achieve the view, desired. The operator will in effect pilot the camera. This allows the operator to explore a particular section of interest while ignoring other sections. However, complete control of a camera in a large domain would be tedious and tiring, and an operator might not view all the important features between the start and finishing point of the exploration.
The second technique of camera control is a planned navigational method, which assigns the camera a predetermined path to take and which cannot be changed by the operator. This is akin to having an engaged “autopilot”. This allows the operator to concentrate on the virtual space being viewed, and not have to worry about steering into walls of the environment being examined. However, this second technique does not give the viewer the flexibility to alter the course or investigate an interesting area viewed along the flight path.
It would be desirable to use a combination of the two navigation techniques described above to realize the advantages of both techniques while minimizing their respective drawbacks. It would be desirable to apply a flexible navigation technique to the examination of human or animal organs that are represented in virtual 3D space in order to perform a non-intrusive painless and thorough examination. The desired navigational technique would further allow for a complete examination of a virtual organ in 3D space by an operator, allowing flexibility while ensuring a smooth path and complete examination through and around the organ. It would be additionally desirable to be able to display the exploration of the organ in a real time setting by using a technique that minimizes the computations necessary for viewing the organ. The desired technique should also be equally applicable to exploring any virtual object.
In practical application, radiological scanning equipment, for example, is used to acquire respective scan data from a patient from both a supine (i.e., face up) and prone (i.e., face down) position. Other than being gathered from the same patient, the image data corresponding to the two orientations are completely independent. As a consequence, when an interesting feature is located in one orientation or view, there is currently no way to automatically “jump” to that same feature in the other orientation or view.